A few days ago, for some reason, my Mi 6 mobile phone could not use usb to connect to the computer.
The main reason is that there is no response after plugging in. Open the device manager and find the portable device showing a yellow exclamation mark (as shown in the figure below, there is a yellow exclamation mark in the lower right corner of the mobile phone icon in front of the MTP USB device).
Right-click the device, select properties, and the device status column displays "Windows cannot verify the digital signature of the driver required by this device..."
After surfing the Internet for a long time, I finally found a solution.